Investigation of temperature fluctuations caused by evaporating meniscus instabilities in two-phase heat transfer devices

两相传热装置中蒸发弯月面不稳定性引起的温度波动研究

• 批准号: RGPIN-2018-05313
• 负责人: Kaya, Tarik
• 金额: $ 1.97万
• 依托单位: Carleton University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=681881
• 关键词: Investigation; temperature; fluctuations; caused; evaporating

The evaporation of a liquid thin film formed in a porous structure and its stability are governed by a complex interaction of mechanisms and among the most challenging problems to study. Our primary goal is to improve the current fundamental knowledge in this field, and thus, to develop the required tools for solving industrial problems involving thin-film evaporation. A better understanding of the underlying physical mechanisms of these phenomena is critical to further improvements in a wide variety of applications, including electronics, fuel-cell, and chemical processing industries.***One of the important areas of application is the thermal control of power generating equipment. As new electronic devices are producing more power and also getting smaller, it is becoming more difficult to remove excess heat by using conventional cooling techniques. High operational temperatures can reduce the life time of electronics, cause performance anomalies and device failures. Therefore, there is a need for more efficient thermal cooling technologies. The most efficient thermal control devices currently available, such as heat pipes, loop heat pipes, and vapor chambers, rely on the evaporation of a liquid thin film. These devices have been used to transfer excess heat from a heat-producing component such as a microprocessor in a computer or an instrument in a spacecraft, while maintaining the temperature within a specified range. The advantages of these devices over other cooling techniques include lack of moving parts, robustness, and the ability to transfer large amounts of heat. ***However, some operational aspects of these devices are still not well understood. One of the major problems associated with these devices is the undesirable temperature fluctuations. Because of the complex phenomena taking place in these devices, mostly qualitative explanations have been proposed for origin of these fluctuations. The temperature fluctuations are highly undesirable as they may hinder the heat removal capacity or cause costly failures.***An improved understanding of the thin-film stability will allow us to investigate the origin of the fluctuations and propose design solutions to ensure a stable operation of these devices. Our previous research has also shown that although the interface instabilities are mostly undesirable, it is feasible to develop new heat transfer enhancement techniques by taking advantage of the instabilities. This is a highly promising area of research and deserves to be further investigated in more detail.***The research will be carried out through both experimental and numerical investigation and involve training of two PhD and two MASc students. The important application areas include electronics cooling, passive cooling of nuclear reactors after an emergency, and thermal control of sensitive space payloads.

在多孔结构中形成的液体薄膜的蒸发及其稳定性受到复杂的相互作用机制的控制，也是最具挑战性的研究问题之一。我们的主要目标是提高该领域当前的基础知识，从而开发解决涉及薄膜蒸发的工业问题所需的工具。更好地理解这些现象的潜在物理机制对于进一步改进各种应用（包括电子、燃料电池和化学加工工业）至关重要。***重要的应用领域之一是热控制发电设备。随着新型电子设备产生的功率越来越大并且体积越来越小，使用传统的冷却技术去除多余的热量变得越来越困难。高工作温度会缩短电子设备的使用寿命，导致性能异常和设备故障。因此，需要更有效的热冷却技术。目前最有效的热控制装置，例如热管、环路热管和均热板，依赖于液体薄膜的蒸发。这些设备已用于传递来自发热部件（例如计算机中的微处理器或航天器中的仪器）的多余热量，同时将温度保持在指定范围内。与其他冷却技术相比，这些设备的优点包括缺乏移动部件、坚固耐用以及传递大量热量的能力。 ***然而，这些设备的一些操作方面仍然没有得到很好的理解。与这些设备相关的主要问题之一是不期望的温度波动。由于这些设备中发生的复杂现象，人们大多对这些波动的起源提出了定性解释。温度波动是非常不受欢迎的，因为它们可能会阻碍散热能力或导致代价高昂的故障。***加深对薄膜稳定性的了解将使我们能够调查波动的根源并提出设计解决方案以确保稳定运行这些设备。我们之前的研究还表明，虽然界面不稳定性大多是不受欢迎的，但利用不稳定性开发新的传热增强技术是可行的。这是一个非常有前途的研究领域，值得进一步进行更详细的研究。***该研究将通过实验和数值研究进行，并涉及对两名博士生和两名硕士生的培训。重要的应用领域包括电子冷却、紧急情况后核反应堆的被动冷却以及敏感空间有效载荷的热控制。